The Department of Justice is suing the owner and operator of the container ship Dali, saying negligence and dangerous cost-cutting decisions led to the ship ramming into — and destroying — Baltimore’s Francis Scott Key Bridge in March.

The catastrophe killed six construction workers and shut down a busy port for months; it also obliterated a segment of Interstate 695 carried by the bridge.

“The ship’s owner and manager … sent an ill-prepared crew on an abjectly unseaworthy vessel to navigate the United States’ waterways,” the Justice Department alleges in a civil claim that was filed on Wednesday in a federal court in Maryland.

Companies, not taxpayers, should pay, DOJ says

The government is suing two Singapore-based corporations, Grace Ocean Private Limited and Synergy Marine Private Limited, seeking more than $100 million in costs the U.S. incurred in responding to the disaster.

“The Justice Department is committed to ensuring accountability for those responsible for the destruction of the Francis Scott Key Bridge, which resulted in the tragic deaths of six people and disrupted our country’s transportation and defense infrastructure,” Attorney General Merrick B. Garland said in a news release.

The civil claim cites costs such as the emergency response to the disaster and the clearing of some 50,000 tons of steel and other materials to create a temporary channel for ships to navigate to and from the port.

Those costs, Garland said, should be “borne by the companies that caused the crash, not by the American taxpayer.”

According to court filings, the ship’s owner, Grace Ocean, and its operator, Synergy, had sought to cap their liability at less than $44 million.

The federal claim does not include the cost of rebuilding the bridge: Because Maryland built and owned the bridge, the state will pursue its own compensation, according to the Justice Department.

The U.S. says the calamity was “entirely avoidable” and was caused by a sequence of failures that resulted in the ship losing power — and thus, its ability to steer.

The claim lays out a sequence of failures, stating that as the ship went into crisis mode with a qualified local pilot at the helm, “none of the four means available to help control the DALI — her propeller, rudder, anchor, or bow thruster — worked when they were needed to avert or even mitigate this disaster.”

The U.S. alleges a string of failures in crucial moments

It all started, the U.S. says, when the Dali’s number 1 step-down transformer — a massive device that converts high-voltage power from diesel generators into usable lower-voltage power — failed as the cargo ship approached the Key Bridge.

The transformer had long been known to suffer from heavy vibrations that raised the risk of an eventual failure, according to the claim. But rather than fix the problem, the Justice Department alleges, the Dali’s owner and operator “jury-rigged their ship,” including welding a large hook into a space in an attempt to brace the transformer.

Here’s how the U.S. claim describes what happened next:

“With the failure at the number 1 step-down transformer, all power stopped flowing to the ship’s 440-volt electrical panel. The bridge and engine room went completely dark, the crew could not steer, and the main engine stopped, which caused the propeller to stop turning. At that point, the power should have transferred automatically to the backup number 2 step-down transformer within just a few seconds, while there was still ample time to steer away from the bridge. But this automation, a safety feature tailor made for the occasion at hand, had been recklessly disabled. The engineers were left struggling in the dark to manually reset the tripped circuit breakers for the number 1 step-down transformer. This took them a full minute, wasting critical time to regain control of the ship.”

Over the next several minutes, none of the backup systems could bring enough power back to the ship to avoid striking the bridge, the Justice Department says.

Under maritime regulations, a container ship that has lost power must be able to tap into an emergency generator within 45 seconds, according to the claim. But, it adds, the Dali drifted onward without power for “well over a minute” after the original blackout.

When power was restored to the helm, the Maryland-based pilot issued orders to steer the ship through the bridge’s central span. But the Dali’s power went out again roughly a minute later. The cause, the claim alleges, was the ship operators’ decision — “made to save money and for their own convenience” — to get fuel to the diesel generators by using a “flushing” pump rather than a standard fuel pump. That arrangement starved the generators, the U.S. says, because the flushing pump on the Dali wasn’t designed with a safety feature requiring it to turn back on automatically after a power outage. As a result, the ship never had its main engine and propeller restored to working order.

With the emergency deepening, the pilot called for the Dali to release an anchor, hoping to pull the ship away from its collision course. But the anchor wasn’t ready to fall.

“By the time the ship finally dropped anchor, less than half a ship’s length from the bridge, it was too late to have any effect,” according to the claim.

Another last-minute emergency order, to send full power to a bow thruster to try to turn the ship, brought the reply that the thruster was “unavailable,” according to an image of the ship’s log in the court document.

The Dali then slammed into a support pier, and sections of the Francis Scott Key Bridge crashed onto the ship and into the Patapsco River.